12820020 (P.T.A.B. Sep. 18, 2017)

Ex Parte Fischer et al

Patent Trial and Appeal BoardSep 18, 2017

12820020 (P.T.A.B. Sep. 18, 2017)

United States Patent and Trademark Office UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O.Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 12/820,020 06/21/2010 Andreas Fischer LAM2P732 1382 119049 7590 09/20/2017 MPG, LLP and Lam Research Corp. Albert Penilla 710 Lakeway Drive Suite 200 Sunnyvale, CA 94085 EXAMINER MACARTHUR, SYLVIA ART UNIT PAPER NUMBER 1716 NOTIFICATION DATE DELIVERY MODE 09/20/2017 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): lamptomail @ mpiplaw. com mpdocket @ mpiplaw .com eofficeaction @ appcoll.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte ANDREAS FISCHER and RAJINDER DHINDSA Appeal 2016-000454 Application 12/820,020 Technology Center 1700 Before PETER F. KRATZ, BEVERLY A. FRANKLIN, and CHRISTOPHER C. KENNEDY, Administrative Patent Judges. KRATZ, Administrative Patent Judge. DECISION ON APPEAL This is a decision on appeal under 35 U.S.C. § 134(a) from the Examiner’s Final Rejection of claims 22 and 24—29. We have jurisdiction pursuant to 35 U.S.C. § 6. Appellants’ claimed invention is directed to a method of configuring plasma chamber for preventing a plasma un-confinement event; that is, an undesired ignition of plasma in spaces outside the intended plasma generating region (Spec. 4, 5, 9). Appellants disclose that adjacent confinement rings can be arranged or adjusted so that the spacing between Appeal 2016-000454 Application 12/820,020 the rings is dimensioned such that the spacing is less than a worst case Debye length of the plasma (Spec. H 9, 25-32).1 Claim 22 is illustrative and reproduced below: 22. A method for configuring a plasma processing chamber for preventing a plasma un-confinement event, during processing of a substrate, from occurring outside of a confined plasma sustaining region, wherein said confined plasma sustaining region is defined by a set of confinement rings disposed at a chamber gap that surrounds a bottom portion of an electrode, said method comprising: (A) determining a worst case Debye length for a plasma generated in said plasma processing chamber during said processing; and (B) performing at least one of adjusting gaps between any pair of adjacent confinement rings and adding at least one additional confinement ring, the performing includes, (Bl) determining that a gap provided between any pair of said adjacent confinement rings is less than the worst-case Debye length that was determined for plasma generated in said processing chamber so as to substantially prevent the plasma un-confmement event from occurring, and (B2) adjusting the gap such that the gap provides a path for exhaustion of byproduct gases from the plasma sustaining region, and the gap does not allow sealing the path for exhaustion of the byproduct gases, 1 Appellants disclose the Debye length of a plasma is a known approach for quantifying a plasma that can be readily calculated, and Appellants disclose that the worst case Debye length relates to Debye length for the worst case plasma density surge (Spec. 131). 2 Appeal 2016-000454 Application 12/820,020 wherein said worst-case Debye length is determined empirically. The Examiner relies on the following prior art references as evidence in rejecting the appealed claims: Huang US 6,117,349 Sept. 12,2000 Han US 6,823,815 B2 Nov. 30, 2004 Chen US 2005/0103442 A1 May 19,2005 Senzaki US 6,899,786 B2 May 31,2005 The Examiner maintains the following grounds of rejection: 1. Claims 22, and 24—26 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Han in view of Huang and Chen. 2. Claims 27—29 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Han in view of Huang, Chen and Senzaki. We reverse the stated rejections for substantially the reasons argued by Appellants (App. Br. 7—12; Reply Br. 3—9). Concerning Rejection 1, the Examiner maintains that Han implies determining a worst case Debye length and suggests adjusting a determined spacing between confinement rings to a distance less than a worst case Debye length in providing an optimal spacing of the confinement rings in light of Applicants’ statement “in the published version of the application paragraphs [0029] and [0030] that the determination of the Debye length is well known in the art and that it is often determined when finding the optimal value of the spacing between the rings in order to make the necessary adjustments to the spacing of the confinement rings” and given 3 Appeal 2016-000454 Application 12/820,020 that “the determination of the worst case Debye length is implied though not specifically stated in that the spacing must be determined to affect the optimal plasma” in Han (Final Act. 3; Ans. 3; Han, col. 2,11. 4—20, col. 4,11. 11- 67; see Spec. H 31, 32). For reasons argued by Appellants, the Examiner’s factual inference based on Appellants’ Specification, on which the rejection is principally predicated, is not supported by the referenced paragraphs in Appellants’ published Application relied upon by the Examiner as an admission by Appellants and/or by the applied prior art (App. Br. 7—11). In this regard, the subject Specification states that “Debye length is one of the more-well known approaches for quantifying a plasma and may be calculated for any plasma”, not that “it is often determined when finding the optimal value of the spacing between the rings in order to make the necessary adjustments to the spacing of the confinement rings” as contended by the Examiner (App. Br. 8; Spec. 131; Final Act. 3). Moreover, Huang is the sole applied reference that discusses Debye length; however, Huang does not discuss a worst-case Debye length (App. Br. 9). Huang discloses that process chamber gaps that exceed a few Debye lengths may result in plasma being extracted into or generated in such sufficiently large gaps or such gaps can cause a gas breakdown in an etch chamber equipped with an E-chuck and a high density plasma (col. 2,11. 13— 65). Huang teaches that limiting gaps between an E-chuck electrode and a shadow ring to less than several Debye lengths is a solution for ideal equipment conditions that cannot be achieved in a manufacturing environment (col. 2,11. 55—65). 4 Appeal 2016-000454 Application 12/820,020 Hence, Huang teaches the use of a composite shadow ring with an inner ring with an upper surface that overlaps an edge of a semiconductor substrate by at least 1 mm and supports an edge of a wafer for preventing the gas plasma from coming in contact with components, including an electrostatic chuck, located in a lower part of the etch chamber (col. 4,11. 30—62). Accordingly, we concur with Appellants that the Examiner has not established how the teachings of Huang, if extended to Han, would have suggested the claimed subject matter (App. Br. 9—10). In sum, the Examiner has not made sufficient factual findings and/or marshalled the applied references teachings in a manner to obviate the Examiner’s incorrect reliance on Appellants’ Specification and otherwise establish that the combination of Han and Huang with or without Chen would have suggested to an ordinarily skilled artisan a method of configuring a plasma processing chamber that would include determining a worst case Debye length for a plasma generated in the plasma processing chamber of Han and configuring the plasma process chamber features to have the gap provided between pairs of adjacent confinement rings dimensioned to be less than the determined worst case Debye length with the confinement ring gap being adjusted or provided so as to include a path that allows for exhausting byproduct gases from a plasma sustaining region as required by the rejected claims (see claim 22). Therefore, we reverse Rejection 1. As for Rejection 2, all of the rejected claims include the claim features argued with respect to Rejection 1, and the Examiner has not established that the additionally applied reference employed therein overcomes the deficiency in the base combination of references applied in Rejection 1. 5 Appeal 2016-000454 Application 12/820,020 It follows that we reverse Rejection 2. CONCLUSION The Examiner’s decision to reject the appealed claims is reversed. REVERSED 6